1 /*
2 * Copyright (c) 2011, 2015, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation.
8 *
9 * This code is distributed in the hope that it will be useful, but WITHOUT
10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
12 * version 2 for more details (a copy is included in the LICENSE file that
13 * accompanied this code).
14 *
15 * You should have received a copy of the GNU General Public License version
16 * 2 along with this work; if not, write to the Free Software Foundation,
17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
18 *
19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
20 * or visit www.oracle.com if you need additional information or have any
21 * questions.
22 */
23 package jdk.vm.ci.hotspot;
24
25 import static jdk.vm.ci.hotspot.HotSpotJVMCIRuntime.runtime;
26 import static jdk.vm.ci.hotspot.HotSpotVMConfig.config;
27
28 import java.lang.annotation.Annotation;
29 import java.lang.reflect.Field;
30
31 import jdk.vm.ci.common.JVMCIError;
32 import jdk.vm.ci.hotspot.HotSpotJVMCIRuntime.Option;
33 import jdk.vm.ci.meta.JavaType;
34 import jdk.vm.ci.meta.LocationIdentity;
35 import jdk.vm.ci.meta.MetaAccessProvider;
36 import jdk.vm.ci.meta.ModifiersProvider;
37 import jdk.vm.ci.meta.ResolvedJavaField;
38 import jdk.vm.ci.meta.ResolvedJavaType;
39
40 /**
41 * Represents a field in a HotSpot type.
42 */
43 class HotSpotResolvedJavaFieldImpl implements HotSpotResolvedJavaField, HotSpotProxified {
44
45 private final HotSpotResolvedObjectTypeImpl holder;
46 private final String name;
47 private JavaType type;
48 private final int offset;
49
50 /**
51 * This value contains all flags as stored in the VM including internal ones.
52 */
53 private final int modifiers;
54 private final LocationIdentity locationIdentity = new FieldLocationIdentity(this);
55
56 public static class FieldLocationIdentity extends LocationIdentity {
57 HotSpotResolvedJavaField inner;
58
59 FieldLocationIdentity(HotSpotResolvedJavaFieldImpl inner) {
60 this.inner = inner;
61 }
62
63 @Override
64 public boolean isImmutable() {
65 return false;
66 }
67
68 @Override
69 public boolean equals(Object obj) {
70 if (this == obj) {
71 return true;
72 }
73 if (obj instanceof FieldLocationIdentity) {
74 FieldLocationIdentity fieldLocationIdentity = (FieldLocationIdentity) obj;
75 return inner.equals(fieldLocationIdentity.inner);
76
77 }
78 return false;
79 }
80
81 @Override
82 public int hashCode() {
83 return inner.hashCode();
84 }
85
86 @Override
87 public String toString() {
88 return inner.getName();
89 }
90 }
91
92 HotSpotResolvedJavaFieldImpl(HotSpotResolvedObjectTypeImpl holder, String name, JavaType type, long offset, int modifiers) {
93 this.holder = holder;
94 this.name = name;
95 this.type = type;
96 assert offset != -1;
97 assert offset == (int) offset : "offset larger than int";
98 this.offset = (int) offset;
99 this.modifiers = modifiers;
100 }
101
102 @Override
103 public boolean equals(Object obj) {
104 if (this == obj) {
105 return true;
106 }
107 if (obj instanceof HotSpotResolvedJavaField) {
108 HotSpotResolvedJavaFieldImpl that = (HotSpotResolvedJavaFieldImpl) obj;
109 if (that.offset != this.offset || that.isStatic() != this.isStatic()) {
110 return false;
111 } else if (this.holder.equals(that.holder)) {
112 assert this.name.equals(that.name) && this.type.equals(that.type);
113 return true;
114 }
115 }
116 return false;
117 }
118
119 @Override
120 public int hashCode() {
121 return name.hashCode();
122 }
123
124 @Override
125 public int getModifiers() {
126 return modifiers & ModifiersProvider.jvmFieldModifiers();
127 }
128
129 @Override
130 public boolean isInternal() {
131 return (modifiers & config().jvmAccFieldInternal) != 0;
132 }
133
134 /**
135 * Determines if a given object contains this field.
136 *
137 * @return true iff this is a non-static field and its declaring class is assignable from
138 * {@code object}'s class
139 */
140 public boolean isInObject(Object object) {
141 if (isStatic()) {
142 return false;
143 }
144 return getDeclaringClass().isAssignableFrom(HotSpotResolvedObjectTypeImpl.fromObjectClass(object.getClass()));
145 }
146
147 @Override
148 public HotSpotResolvedObjectTypeImpl getDeclaringClass() {
149 return holder;
150 }
151
152 @Override
153 public String getName() {
154 return name;
155 }
156
157 @Override
158 public JavaType getType() {
159 // Pull field into local variable to prevent a race causing
160 // a ClassCastException below
161 JavaType currentType = type;
162 if (currentType instanceof HotSpotUnresolvedJavaType) {
163 // Don't allow unresolved types to hang around forever
164 HotSpotUnresolvedJavaType unresolvedType = (HotSpotUnresolvedJavaType) currentType;
165 ResolvedJavaType resolved = unresolvedType.reresolve(holder);
166 if (resolved != null) {
167 type = resolved;
168 }
169 }
170 return type;
171 }
172
173 public int offset() {
174 return offset;
175 }
176
177 @Override
178 public String toString() {
179 return format("HotSpotField<%H.%n %t:") + offset + ">";
180 }
181
182 @Override
183 public boolean isSynthetic() {
184 return (config().jvmAccSynthetic & modifiers) != 0;
185 }
186
187 /**
188 * Checks if this field has the {@link Stable} annotation.
189 *
190 * @return true if field has {@link Stable} annotation, false otherwise
191 */
192 public boolean isStable() {
193 if ((config().jvmAccFieldStable & modifiers) != 0) {
194 return true;
195 }
196 assert getAnnotation(Stable.class) == null;
197 if (Option.ImplicitStableValues.getBoolean() && isImplicitStableField()) {
198 return true;
199 }
200 return false;
201 }
202
203 @Override
204 public Annotation[] getAnnotations() {
205 Field javaField = toJava();
206 if (javaField != null) {
207 return javaField.getAnnotations();
208 }
209 return new Annotation[0];
210 }
211
212 @Override
213 public Annotation[] getDeclaredAnnotations() {
214 Field javaField = toJava();
215 if (javaField != null) {
216 return javaField.getDeclaredAnnotations();
217 }
218 return new Annotation[0];
219 }
220
221 @Override
222 public <T extends Annotation> T getAnnotation(Class<T> annotationClass) {
223 Field javaField = toJava();
224 if (javaField != null) {
225 return javaField.getAnnotation(annotationClass);
226 }
227 return null;
228 }
229
230 private Field toJavaCache;
231
232 private Field toJava() {
233 if (toJavaCache != null) {
234 return toJavaCache;
235 }
236
237 if (isInternal()) {
238 return null;
239 }
240 try {
241 return toJavaCache = holder.mirror().getDeclaredField(name);
242 } catch (NoSuchFieldException | NoClassDefFoundError e) {
243 return null;
244 }
245 }
246
247 private boolean isArray() {
248 JavaType fieldType = getType();
249 return fieldType instanceof ResolvedJavaType && ((ResolvedJavaType) fieldType).isArray();
250 }
251
252 private boolean isImplicitStableField() {
253 if (isSyntheticEnumSwitchMap()) {
254 return true;
255 }
256 if (isWellKnownImplicitStableField()) {
257 return true;
258 }
259 return false;
260 }
261
262 public boolean isDefaultStable() {
263 assert this.isStable();
264 if (isSyntheticEnumSwitchMap()) {
265 return true;
266 }
267 return false;
268 }
269
270 private boolean isSyntheticEnumSwitchMap() {
271 if (isSynthetic() && isStatic() && isArray()) {
272 if (isFinal() && name.equals("$VALUES") || name.equals("ENUM$VALUES")) {
273 // generated int[] field for EnumClass::values()
274 return true;
275 } else if (name.startsWith("$SwitchMap$") || name.startsWith("$SWITCH_TABLE$")) {
276 // javac and ecj generate a static field in an inner class for a switch on an enum
277 // named $SwitchMap$p$k$g$EnumClass and $SWITCH_TABLE$p$k$g$EnumClass, respectively
278 return true;
279 }
280 }
281 return false;
282 }
283
284 private boolean isWellKnownImplicitStableField() {
285 return WellKnownImplicitStableField.test(this);
286 }
287
288 static class WellKnownImplicitStableField {
289 /**
290 * @return {@code true} if the field is a well-known stable field.
291 */
292 public static boolean test(HotSpotResolvedJavaField field) {
293 return field.equals(STRING_VALUE_FIELD);
294 }
295
296 private static final ResolvedJavaField STRING_VALUE_FIELD;
297
298 static {
299 try {
300 MetaAccessProvider metaAccess = runtime().getHostJVMCIBackend().getMetaAccess();
301 STRING_VALUE_FIELD = metaAccess.lookupJavaField(String.class.getDeclaredField("value"));
302 } catch (SecurityException | NoSuchFieldException e) {
303 throw new JVMCIError(e);
304 }
305 }
306 }
307
308 public LocationIdentity getLocationIdentity() {
309 return locationIdentity;
310 }
311 }